Histogram of Oriented Gradient descriptors, or HOG descriptors, are feature descriptors used in computer vision and image processing for the purpose of object detection. Algorithms associated with HOG descriptors have been used to identify or otherwise distinguish particular features of a static image or video from the background. For example, HOG descriptors have been used to identify a particular vehicle in a satellite image. Additionally, HOG descriptors have been used to distinguish a human profile from the background of a photograph.
Specific emitter identification (SEI) typically involves accurately measuring and storing signal features that are consistent from one transmission to another for a given emitter, but differ from emitter to emitter. A particular emitter may then be identified by attempting to match measured emissions with previously stored emissions. Convention SEI matching methods are limited for a variety of reasons.